Classic Crawfish Etouffee

  Serves 4 1 cup onion, chopped 1/4  cup butter + 1 tbs. 1/4 cup All Purpose flour 1/4 cup celery, chopped 1/4 cup sweet green pepper, chopped 2 tbs. garlic, minced 1 tbs. tomato paste 2 tsp. salt 1 lb. Louisiana crawfish tail meat, including fat   1/2 tsp....